Condenser



June 2, 1925. 1,540,176

F. P. MARSH CONDENSER Filed June 25. 1922 2 Sheets-Shaet l June 1925' 1,540,176

F. P. MARSH commnssa Filed June 23. 1922 zhshaets-shaet 2 Patented June 2, 1925.

UNITED STATES FRANK P. MARSH, 01' NEW HAVEN. CONNECTICUT.

CONDENSER.

Application filed June 23, 1922. Serial No. 570,398.

To all whom it may concem:

Be it known that I, FRANK P. Mansn, a citizen of the United States, residing at New Haven, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Condensers, of which the following is a specil'ication.

This invention relates to condensers, and

more particularly to a condenser having an auxiliary movable plate for obtaining fine adjustments.

In the present invention, I provide a condenser consisting of a set of stationary plates anda secondset of movable lates arranged alternate therewith and a apted to be adjusted to. vary the capacity of the condenser. I

I further provide an auxiliary movable plate which may be further adjusted for the purpose of obtaining fine adjustments after a rough adjustment has been. obtained by means of the plurality of movable lates.

I am aware that it has heretoore been proposed to employ an auxiliary movable plate in a varia le condenser of this type, but in the present invention, I provide an improved construction in which the auxiliary plate may be moved with the main set :10 of plates and may be further adjusted independently without first locking the main plates.

An object of the invention is 'the provision of means for quickly obtaining adjustments.

A' further object is the provision of a variable condenser of this type that can be quickly and easily connected to a. radio set and may be either placed upon a table or support or mounted ona panel board.

A further ob'ect is the provision of a clutch bearing aving fingers ada ted to exert an inward pressure on the s aft to maintain a perfect bearing at all times.

In the accom anying drawings, I have shown one embo iment of the invention. In this showing:

Figure 1 1s a front elevation,

Figure 2 is a side elevation,

Figure 3 is a rear elevation,

Figure 4 is a vertical longitudinal sectional view, I

Figure 5 is a transverse vertical sectional view on line 5-5 of Figure 2. Figure 6 is a similar view on line 6-6 of Figure 2, and,

Figure 7 is a detail view of the bearing.

Referring to the drawings, the reference numeral designates a top plate and 2 a bottom plate of insulating material. These plates are connected by a plurality of posts or standards 3. As shown, the standards are secured to the top plate by means of screws 4. The standards are provided with portions 5 which are circular in cross section and threaded on their other ends, as at 6. These threaded portions pass through openings in the bottom plate and are adapted to receive nuts 7. The stationary plates 8 are arranged on the standards and supported thereby. These plates are separated by means of sleeves 9 to provide spaces for the n'iovable plates. As shown, a movable plate 10 is arranged between each pair of stationary plates. The bottom movable plate 11 is independently adjustable and is adapted to be moved after the plates 10 have been adjusted to obtain a finer adjustment.

As shown, a shaft 12 extends through the condenser from top to bottom and is surrounded at its outer end by asleeve 13. The shaft and sleeve pass through a. bearingrarranged in the top plate. bearing consists of a ring 14, forming a flange engaging the under side of the top plate and a plurality of fingers 15, separated from each other by slots 16. These fingers are adapted to exert an inward pressure on an extension 17 of the sleeve to maintain a perfect bea'ringat all times. This extension is adapted to receive a plate 18 having suitable indicia l9 thereon, to indicate degrees.- The plate is secured to the sleeve by means of a set screw 20, passing through a sleeve 21 of insulating material carried by the plate 18. The shaft 12 extends through the sleeve, as indicated in dotted lines in Figure 4 of the drawings, and a knob 22 is secured thereto bymeans of a set screw 23. A second knob 24 is secured to the sleeve 21. The movable plates 10 are provided with openings for the reception of the shaft and As shown, the Y are separated from each other by sleeves or collars 25. adapted to turn with the shaft.

These collars frictionally engage the plates and cause the plates to turn with the sleeves 13 when the knob 24 is turned; The auxil iary plate 11 is mounted between a pair of collars 26 and is adapted to turn with the main plates. The bottom collar 26 is provided with a set screw 27 which secures it to the shaft 12. The end of this collar fricllO I of the bottom tionally engages the plate 11 whereby the plate isrevolved with the shaft. A spring 28 is secured to the under side of the top plate by means of a screw 29 and this spring is provided with a forked end 30, adapte to contact with the sleeve 13. As shown the sleeve 13 is provided with a radially pro ecting pin 31, adapted to engage stops 32 to limit the movement of the movable plates. A spring 33 is arranged on the outer side late, being secured thereto by means of a olt 34, and a nut 35. The outer end of this spring is offset, as at 36, and is adapted to exert a pressure on the shaft 12. A threaded post 36 passes through the spring and a nut 37 is provided to ob- .tain the desired tension on the end of the shaft.

In operation, lead wires are connected to one of the posts 6 by means of nuts 7 and to the post 36 by means of nuts 37. The stationary plates are thus connected to one end of the circuit and the movable plates to the other end. The condenser is roughly adjusted to the desired capacity by turning the plates 10. When the knob 24 is revolved, the sleeve 13 is turned through extension 17, and by frictional contact, the collars or sleeves 25 and the plates 10 and 11 are turned. The amount of ad'ustment may be ascertained by means of in icia 19 on plate 18. When the condenser has been roughly adjusted, the knob 22 may be turned to revolve the shaft 12. The bottom sleeve 26 is revolved with the shaft, thus adjusting the plate 11. The principle involved is similar to the operation of a micrometer. Movement of the entire body of adjustable plates varies the capacity of the condenser to a considerable degree, whereas the single plate 11 may be moved without great variation in the capacity of the condenser to obtain a very fine ad'ustment.

It Wlll be noted that the movable plates may be set and the auxiliary plate 11 then adjusted without looking the main body of movable plates, which provides a quick adjustment, necessary in radio work.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the 'rality of stationary lates mounted on said posts, a shaft exten ingbetween said end members, collars mounted on said shaft, a

sleeve mounted on said shaft and extending through one of said end members, movable plates arranged between said collars to turn therewith, a knob mounted on said sleeve, a shaft extending through said movable plates and said collars and adapted to rotate independently thereof, an independent movable plate secured to said shaft near one of said end members, and arranged between a pair of said stationary plates, and a collar secured to said shaft and arranged between said independent movable plate and the ad'acent end member, said last named collar eing secured tosaid shaft and contacting with said end member, said shaft havin one end journaled in said sleeve and provided with a knob and its 0 posite end extending througllei and journals 1n the opposite end mem r.

2. A device constructed in accordance with claim 1 provided with a bearin member carried by one of said end mem rs and surrounding and resiliently engaging said sleeve.

3. A device constructed in accordance with claim 1 provided with a resilient electrical contact member frictionally engaging the end of said shaft which is journaled in said end plate.

In testimony whereof, I afiix my signature in presence of two witnesses.

FRANK P. MARSH.

i Witnesses:

EDWARD N. Bammic'r, Cms. J. Run. 

